Dear Amy: My best friend of almost 17 years has a bad temper. Some days she will be all dandy and happy, but other days she is a completely different person.

Lately she has been acting even worse when we are alone, but she seems to treat others better. This annoys me to no end, and it has come to the point that I avoid her because I never know what mood she will be in.

I can’t stand to see one of my longest-lasting friendships die. I’ve thought about ending the relationship with a clean break, but somehow I can’t bring myself to do it.

She is dear to me, and I can’t stand the thought of not having her as a friend. I’ve begun to wonder if she acts out only with me because she doesn’t feel the need to continue the relationship, or if because we’ve known each other for so long she feels comfortable to show her true colors.

I feel as if I am the only one contributing to the friendship. She tends to degrade me, I think, to make herself feel better, while I try to encourage her and make her feel better about herself with kind gestures.

This friendship has worn me down. Should I keep trying to fix it or let her go her own way? — Friend Indeed

Dear Friend: Like the phases of the moon, friendships — most relationships, really — wax and wane. Sometimes they burn brightly, illuminating the world. And sometimes they burn out.

You are reluctant to give up on this long-term friendship, and that speaks well of you. You are also tolerating an escalating level of abuse and degradation, which makes me wonder about you.

Your friend might be bipolar, hormonal or just plain moody or mean. Your job isn’t to diagnose her. The best you can do is inject some clarity into your murky and disintegrating relationship by telling her, “I feel as if I’m the only one contributing to our friendship. Your worst moods seem reserved for me, so what’s up with that?”

If you have a simple and honest conversation — not confrontation — your friend’s reaction will tell you what to do next.

Dear Amy: I am responding to the letter from the guy who lived in New England and was extremely affected and depressed by the harsh winters.

Perhaps this advice will shorten his winter: Simply borrow a large sum of money on the last day of fall and sign a promissory note to pay it back in full on the first day of spring. — Vernon

Dear Vernon: Nothing makes the calendar fly by on winged feet quite like owing a large sum of money.